I have the same concerns as Jeff [Oliver, 20 Oct 1996]. Who were the 36 undergraduate students in teacher training? It's implied from the paper that the students were from the University of Aizu in Japan where Steve teaches. If this is the case then the students are not "average" students, because the University of Aizu is a university that specializes in computer science and engineering.
Steve, could you provide us with more information about the subjects? Also, was the information presented to the subjects in their native language? Was the audio portion recorded by a native speaker?